Finally my Scanner reported the Cylinder #4 Misfire

AmsterDutch

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After battling a P0172 code since purchasing the car about a month ago... Finally had my OBDII reader pick up a misfire on cylinder 4... the car has had a ROUGH IDLE and the P0172...I guess I wanna know what are your thoughts on this? Was this Marginalized misfire creating the car to produce a P0172 or would P0172 cause Cylinder 4 Misfire? I can see that the COP's look to be cheap aftermarket off Ebay/Amazon so Yes I need to spend the $500 on new COP's but due to hearing what sounds like a rattle I've been hesitant until my Mechanic checks out the chains....but now I'm thinking the rattle could be an what I think is the idler pulley...Don't want to beat a dead horse but I still feel like I'm chasing my tail here due to the fact my last 2001 V8's engine purred like a kitten the whole 5 years I had it...I was thinking this could be leaking injectors, is there anyway to tell if the injectors truly are the culprit without bringing the car to a shop and having them run expensive tests? any thoughts or advise appreciated
 
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C'mon now Dutch, you know better!

"would P0172 cause Cylinder 4 Misfire?"

No, otherway around.

"System Too Rich (Bank 1)"

"Too Rich" means too much fuel, not enough air. (raw fuel)

Where do we keep Cyl #4 ?
Occasional Misfires will cause raw fuel to be send downstream.

Pre CAT Oxygen sensor reports value, PCM adjusts Fuel/Air trim.
... eventually reaches outside it's allowable tolerance,
PCM says, too much to adjust for, can't adjust any further,
stores an emissions fault code indicated by the DTC




... just do a nice clean NGK Plug & OEM DG529 coils job on it.
Air & fuel filter, MAF cleaned, STP in the tank.

Clear codes and have another look.


.
 
Seems like misfires usually cause lean codes.
Misfire = no/poor combustion = too much oxygen left over = sensors thinks lean
Remember they measure left over oxygen, not left over fuel.
(Just a counter thought...)
 
Hmmmm, always went by too much fuel, not enough air.


P0172 indicates that there is too much gasoline being detected in the exhaust gases exiting the combustion chamber. ... The term “rich” in this case means that there is too much gasoline and not enough oxygen detected in the air-fuel ratio of the engine.


Albeit, P0172 is not a misfire code.
 
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Hmmmm, always went by too much fuel, not enough air.


P0172 indicates that there is too much gasoline being detected in the exhaust gases exiting the combustion chamber. ... The term “rich” in this case means that there is too much gasoline and not enough oxygen detected in the air-fuel ratio of the engine.


Albeit, P0172 is not a misfire code.

Thanks for the response but now you and Joe have me pretty confused...I have some OEM vacuum seals ordered and will be installing those with MotorCraft COPs and NGK Iridium plugs Saturday I'll keep you guys posted if it improves things
 
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Clean the MAF also as it's playing an important role in determining that current fault code.
From what I can tell, it's possible the MAF is telling it to adjust one way, whilst the O2 Sensor is telling it to adjust the other way.

See this entire page, you'll note the confusion.
P0172 and P0175 - OBD-II Trouble Codes

When the P0172/P0175 code sets, the oxygen sensors are detecting too little oxygen in the exhaust and the control module is removing the maximum amount of fuel in its effort to maintain the proper air/fuel mixture.


(I had to review everything myself yesterday after Joe's comment)



Just cover the basics, clean strong spark, good fuel & air.
Check the entire plastic intake snorkel/clamps for any possible un-metered air entering after the MAF.
Might also be a good idea to run an unlit propane torch around all the intake and such. slight increase in RPM would indicate a leak.



As far as getting a better understanding of what the tentioners are doing (re: rattling/ticking noise), try and lean the butt end of a large screwdriver on your ear and the other metal end resting on top of where the tentioner and chains would be. At idle listen for the noise, if it's the rattling/ticking, you should be able to hear it magnified. Listen to see if it's in rhythm with the sound you are hearing without.

Fuel injectors 'can' become noisy also.


~ Good luck, you know these things are very temperamental on the ignition.


.
 
Clean the MAF also as it's playing an important role in determining that current fault code.
From what I can tell, it's possible the MAF is telling it to adjust one way, whilst the O2 Sensor is telling it to adjust the other way.

See this entire page, you'll note the confusion.
P0172 and P0175 - OBD-II Trouble Codes

When the P0172/P0175 code sets, the oxygen sensors are detecting too little oxygen in the exhaust and the control module is removing the maximum amount of fuel in its effort to maintain the proper air/fuel mixture.


(I had to review everything myself yesterday after Joe's comment)



Just cover the basics, clean strong spark, good fuel & air.
Check the entire plastic intake snorkel/clamps for any possible un-metered air entering after the MAF.
Might also be a good idea to run an unlit propane torch around all the intake and such. slight increase in RPM would indicate a leak.



As far as getting a better understanding of what the tentioners are doing (re: rattling/ticking noise), try and lean the butt end of a large screwdriver on your ear and the other metal end resting on top of where the tentioner and chains would be. At idle listen for the noise, if it's the rattling/ticking, you should be able to hear it magnified. Listen to see if it's in rhythm with the sound you are hearing without.

Fuel injectors 'can' become noisy also.


~ Good luck, you know these things are very temperamental on the ignition.


.
Thanks for the clarity Rigs ... My fear is I do have a intake air leak and I thought heard they don't make intake gaskets anymore I could be wrong I will try the screw driver trick also but I'm thinking I need new manifold rings and gaskets I think I'm saying that right I can smell oil through my vents in the cab when driving so I'm sure they are leaking I will look at chains when the manifold cover is off ...I'm hoping the new seals/grommets takes care of the P0172 code... By the way I replaced the Maf already I'll keep you posted off to work I go.. Gotta run
 
Most, if not all of the intake related gaskets are still available (but not all from Ford).
What do you mean by "manifold rings?"
I've lost track, this is a V8, right? No oil passages in the V8 intake. The only oil in there would be from the PCV. It wouldn't leak out while running due to the vacuum. It's much more likely to be from the valve cover gaskets.
I don't see any reason to wait till after taking the intake manifold (assuming this is what you are calling "manifold cover") off to take the valve covers off to look at the chains.
 
Most, if not all of the intake related gaskets are still available (but not all from Ford).
What do you mean by "manifold rings?"
I've lost track, this is a V8, right? No oil passages in the V8 intake. The only oil in there would be from the PCV. It wouldn't leak out while running due to the vacuum. It's much more likely to be from the valve cover gaskets.
I don't see any reason to wait till after taking the intake manifold (assuming this is what you are calling "manifold cover") off to take the valve covers off to look at the chains.
Yes valve cover gaskets is what I meant thanks for the correction Joe and that's good news that I can still get the intake gaskets still disappointing they might have to be aftermarket and yes it's a V8 my brain was scattered while getting ready for work need to refrain from responding before work from now on lol
 
Replaced all Cop’s & plugs OEM and just for good measure replaced Bank 1 sensor 1 pre-Cat O2 sensor and still have more smoke coming from left rear tail pipe and P0304 is still reading on OBDII scanner ....back to the drawing board.... tomorrow I will switch #3 COP and plug with #4 and if #4 cylinder still misfires after swapping the two I can rule out spark plug and Coil-over-plug (COP) I can see oil running out of valve cover bolt on the right side hitting the manifold ...hence the smell of oil in the cabin is confirmed... I will need new valve cover gaskets and tubes ...now the question that comes to mind is this....is the injector stuck open on #4 cylinder or should I do a cigar smoke test next to see if intake gaskets are shot...I’m going to figure this out ...I have the patience but still like others thoughts? Thanks
 
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I think I just found the Holy Grail of Coil over Plug Threads ...With that being said I need to do a lot of work to this car before I even think about writing another post...I prematurely jumped the gun here...it could be several things why I'm getting a misfire...see you guys in about 6 months lol
 
Good news and bad news ...the good news is no more misfires I swapped out #4 COP and PLUG with #1 COP and Plug and the misfire went away ...or at least for now I might not have positioned the COP just right or something , who knows they are so finicky...also I finally hear what sounds like a high pitch whistle so more than likely I have a vacuum leak it’s hard to tell where it’s coming from though ...it almost sounds like it’s under the intake which seems kinda strange but more investigation is needed...bad news is the P0172 and P0174 codes are back
 
thought p0304 was mis num 4 and 171 174 was insufficient ive got a 02 that had that prob for a run it was the crank case venti tube going into the aircleaner and rainwater in my #4 ….drips from the wiper park came down the seem onto the cop cover during a cam tensioner job after duct taping the crank gas hose to the aircleaner and blowing out the coil cover ...back to no DTC's made adjustments to wiper park area made shure the nuts were snug on the cop covers ….cops again ….my next magic word is egg..erzz
 
thought p0304 was mis num 4 and 171 174 was insufficient ive got a 02 that had that prob for a run it was the crank case venti tube going into the aircleaner and rainwater in my #4 ….drips from the wiper park came down the seem onto the cop cover during a cam tensioner job after duct taping the crank gas hose to the aircleaner and blowing out the coil cover ...back to no DTC's made adjustments to wiper park area made shure the nuts were snug on the cop covers ….cops again ….my next magic word is egg..erzz
Yes you’re absolutely right P0304 is #4 misfire...I was thinking egr could possibly clear up my rich and lean issue but I’m leaning more towards a timing chain issue I will be doing valve cover gaskets this month and will see if my chain skipped a tooth when there off ...I cleared up the misfires this weekend by replacing plugs and COPS but I fear it will only be temporary...I also have replaced two O2 sensors pre-cat on both banks and still I have the P0172 and P0174 Bank 1 is rich and Bank 2 is lean at the same time ....from what I read on the LVC forum it’s more than likely a skipped tooth as I said previously but I’m always the optimistic and hope it’s something easier so I have a evap canister on the way and I will also be replacing EGR valve solenoid if that doesn’t work it’s off to my mechanic to have a new chain kit
 

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